4.0 Study Area Biology and Land Use

4.0 Plan Area Biology and Land Use

4.1 Setting

The NCCP/HCP Plan Area covers approximately 992,000 acres in western County and southwestern Riverside County. This diverse geographic landscape includes flat, relatively gentle slopes on the coastal terraces, mesas, broad river valleys, and steep hills and mountains in the inland portions. Topographical features include coastal beaches; mesas, canyons and rolling hills; plains, buttes, and plateaus; foothills and mountains; and rivers, creeks and drainages. Steep canyons are associated with drainages that have cut through hills and mesas. Intermittent streams flow down the slopes into canyons, eventually merging with one of the several major rivers that terminate in lagoons and estuaries near the Pacific Ocean.

San Diego County has a characterized by warm, dry summers and mild, wet winters. Annual precipitation in the NCCP/HCP area varies from less than 11 inches near the coast to more than 25 inches farther inland near the . The Plan Area contains more than 100 different soil types that range in texture and qualities, such as erodibility and expansion. The range in soil types is a result of many factors, including the underlying bedrock, temperature, saturation, and plant cover.

As a result of diverse topography and microclimates, a number of unique and communities that support a host of native plant and wildlife species occur within the Plan Area. Nevertheless, human activities have modified many of the region’s plant communities and replaced large tracts of native vegetation with agriculture and urban development, especially in the western portion of the Plan Area.

The Water Authority has fee ownership or easements/rights-of-ways in the Plan Area. Many facilities and easements in the Plan Area are located along the linear aqueduct system that traverses north-south routes from southwestern Riverside County to southern San Diego (see Figure 1-2).

4.1.1 Database Development

Information on the vegetation communities and Covered Species addressed in this Plan was developed from reviews of existing GIS data bases (primarily the San Diego County SanGIS database and Natural Diversity Database, CNDDB), previously prepared regional conservation plans for San Diego and western Riverside counties, species occurrence records from the San Diego Natural History Museum, and field assessments by Water Authority staff and environmental contractors. This information addresses biological information collection recommendations by the Independent

4-1 4.0 Study Area Biology and Land Use

Science Advisors and represents the best available scientific information for the vegetation communities and Covered Species.

The SanGIS database is maintained by the county and city of San Diego and was created or obtained from many sources. Some data was created from tabular digital files; some data was digitized from paper maps; and other data was entered using coordinate geometry tools. It includes over 400 geographic data layers, such as vegetation, land use/zoning, roads, parcels, etc. SanGIS staff is responsible for coordinating with other data maintainers to ensure currency and accuracy for all participants. All of the SanGIS geographic data is within San Diego County. The accuracy of the data varies between themes and within themes depending on the source documents used to create the data. Most of the source documents used for SanGIS data was at one inch equals 200 feet or one inch equals 400 feet, making it more accurate than many other GIS data sources. According to SanGIS’s website, the SanGIS data has an overall accuracy of plus or minus 10 feet.

CNDDB is a "natural heritage program" and is part of a nationwide network of similar programs overseen by NatureServe (formerly part of The Nature Conservancy). All natural heritage programs provide location and natural history information on special status plants, animals, and natural communities to the public, other agencies, and conservation organizations. The data help drive conservation decisions, aid in the environmental review of projects and land use changes, and provide baseline data helpful for endangered species recovery efforts and research projects.

The goal of the CNDDB is to provide the most current information available on California's most imperiled elements of natural diversity and to provide tools to analyze these data. The CNDDB concentrates its work on areas with active NCCP/HCPs, and high priority areas identified by CDFG and other biologists. The primary method of data dissemination is via the computer application RareFind, which allows for complex querying and reporting by the user. For GIS users, a shapefile of the entire CNDDB dataset is available.

Information was also obtained from the MSHCP, San Diego MSCP, and San Diego MHCP. Conservation plans prepared under those programs provided relevant information on land use, vegetation distribution, and species occurrences.

The San Diego Natural History Museum (SDNHM) maintains extensive records for plant and animals occurrences in San Diego County. Records were reviewed to update and fill-in apparent gaps in species’ information after the preceding information sources were utilized.

As projects and activities were conducted by the Water Authority since inception of the Plan, biological specialists have field-verified vegetation conditions, disturbed areas, and uses over portions of land both within and outside the various rights-of-way and facilities.

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This site-specific data is continually refined and updated as projects are planned and implemented.

4.2 Vegetation Communities and Types

Habitat and vegetation communities in the Plan Area reflect the diverse topography and climate of the region. As a result, a large number of habitat and vegetation types that support a host of native plant and wildlife species exist within the Plan Area. The distribution of vegetation communities occurring within the Plan Area is shown in Figure 4-1.

Vegetation communities found within the Plan Area include coastal fringe environments, freshwater , sage scrub, , grasslands, woodlands, high foothill, montane, and vernal pool habitats. Other land types include agricultural and non-native landscapes, as well as developed and urbanized lands. Vegetation community classifications follow Holland (1986) as modified by Oberbauer (2005) and Sawyer and Keeler-Wolf (1995). Floral nomenclature for common plants follows Hickman (1993). Specific definitions for communities follow the North County MHCP Volume II Appendix F (SANDAG 2003) and the MSHCP’s Riverside County Integrated Project (RCIP 2003).

Figure 4-1 displays the generalized vegetation communities and land cover types within the Plan Area based on regional vegetation community mapping from SanGIS that was most recently updated in 2007. The acreage of each vegetation or land cover type and subcommunity is shown for both the Plan Area and the PIZ in Table 4-1. Because the majority of vegetation mapping was performed at a landscape level (i.e., large scale), the vegetation subcommunities listed in this table have been further refined in some cases to better represent vegetation communities known to occur in the region. Although there are subcommunities that have not been distinctly mapped within the Plan Area or the PIZ, it is anticipated that site specific surveys in the area of proposed Covered Activities may reveal some of these specific subcommunities.

Table 4-2 provides the terminology used in the Plan in comparison to terminology used in other regional planning documents.

4-3 ORANGEORANGE COUNTYCOUNTY

RIVERSIDERIVERSIDE COUNTYCOUNTY

SANSAN DIEGODIEGO COUNTYCOUNTY

P a c i f i c O c e a n

ATES UNITED ST Map source: CWA, January 2009 0 Miles 10 [ NCCP/HCP Plan Area Aquatic Marine Disturbed/Developed Riparian Probable Impact Zone Aquatic Freshwater Grasslands Sage Scrub (PIZ) Chaparral Non-Native Vegetation Wetland Vegetation Communities/ Land Cover Types Coastal Oak Woodland and Forest Agricultural Coniferous Forest Disturbed Riparian FIGURE 4-1 Vegetation Communites/Land Cover Types M:\JOBS2\3639\env\gis\NCCP\Fig4-1_NCCP.mxd 8/6/2010 in the NCCP/HCP Plan Area TABLE 4-1 APPROXIMATE AREA OF VEGETATION COMMUNITIES/LAND COVER TYPES (acres)

Approximate Area1 Vegetation Community/Land Cover Type and Subcommunities Plan Area PIZ Upland Habitats Agricultural 123,240 11,469 General Agriculture 12,348 2,092 Extensive Agriculture (Row Crops, Pastures) 39,055 2,597 Intensive Agriculture (Dairies, Nurseries, Chicken Ranches) 5,189 259 Orchards and Vineyards 66,648 6,521 Chaparral, Coastal 142,204 8,139 Chamise Chaparral (Granitic Chamise Chaparral) 5,425 29 Chaparral2 36,025 1,664 crassifolius Chaparral 4,231 0 Interior Live Oak Chaparral 00 Northern Mixed Chaparral 140 0 Northern Mixed Chaparral (Granitic) 14 0 Northern Mixed Chaparral (Mafic) 10 Scrub Oak Chaparral 301 0 Southern Maritime Chaparral 3,025 4 Southern Mixed Chaparral (Granitic) 92,848 6,435 Southern Mixed Chaparral (Mafic) 194 7 Chaparral, Montane/Trans-montane 0 0 Montane Chaparral 00 Redshank Chaparral 00 Coastal 459 0 Open Beach 301 0 Southern Foredunes 158 0 Coniferous Forest 902 0 Big Cone Spruce- Canyon Oak Forest 721 0 Mixed Coniferous Forest 20 Southern Interior Cypress Forest, Tecate Cypress Forest 17 0 Torrey Pine Forest 162 0 Disturbed/Developed 378,251 25,024 Bare Ground 00 Disturbed 352,165 1,387 Urban/Developed Land 26,086 23,637 Grasslands 100,579 6,222 Native Grassland (Valley Needle Grassland, Valley and Foothill Grassland) 52,635 2,705 Non-Native Grassland (Grassland) 47,944 3,517 Exotic Landscapes 2,851 215 Eucalyptus/Non-native vegetation 2,851 215 Ornamental 00 Oak Woodland and Forest 17,548 775 Black Oak Forest 28 0 Black Oak Woodland 781 33 Coast Live Oak Forest (Dense Coast Live Oak Woodland) 2,246 103 Coast Live Oak Woodland (Open Coast Live Oak Woodland) 9,976 636 Engelmann Oak Forest (Dense Engelmann Oak Woodland) 2,837 2 Engelmann Oak Woodland (Open Engelmann Oak Woodland) 1,391 1 Mixed Oak Woodland (Oak Woodland) 289 0

4-5 TABLE 4-1 APPROXIMATE AREA OF VEGETATION COMMUNITIES/LAND COVER TYPES (acres)

Approximate Area1 Vegetation Community/Land Cover Type and Subcommunities Plan Area PIZ Sage Scrub, Coastal 179,708 9,856 Alluvial Fan Scrub 133 0 Cactus Scrub 00 Coastal Sage-Chaparral Scrub 15,933 368 (Diegan) 160,215 8,534 Coastal Sage Scrub (Inland) 302 500 Flat-topped Buckwheat Scrub 103 0 Maritime Succulent Scrub 1,434 35 Riversidean Alluvial Fan Scrub 172 14 Riversidean Sage Scrub 1,131 405 Southern Coastal Bluff Scrub 285 0 Sage Scrub, Montane/Trans-montane 4 0 Big Sagebrush Scrub (Great Valley) 40 Undefined3 1,627 0

Wetland Habitats Aquatic Freshwater 8,529 1,638 Non-vegetated Floodplain, Channel, Lakeshore Fringe 2,316 0 Open Freshwater (Freshwater, Open Water, Water) 6,213 1,639 Aquatic Marine 1,365 0 Open Saltwater (Brackish Water, Deep Bay, Estuarine, Intertidal, Shallow Bay, Subtidal) 1,189 0 Saltpan/Mudflats 176 0 Riparian 29,231 1,132 Arrowweed Scrub 00 Mule Fat Scrub 830 60 Southern Arroyo Willow Riparian Forest 413 5 Southern Coast Live Oak Riparian Forest 6,023 207 Southern Cottonwood-Willow Riparian Forest 6,079 377 Southern Sycamore Woodland 00 Southern Sycamore-Alder Riparian Woodland 3,999 151 Southern Willow Scrub 11,867 332 White Alder Riparian Forest 20 0 Riparian (Disturbed) 457 4 Arundo Scrub 14 0 Tamarisk Scrub 443 4 Wetland 5,351 125 Alkali (Alkali Seep, Alkali Marsh, Cismontane Alkali Marsh) 921 34 Freshwater Meadow or Seep 148 11 Freshwater Marsh (Coastal and Valley Freshwater Marsh, Emergent Wetland) 1,397 36 Montane Meadow 30 Southern Coastal Salt Marsh 1,837 0 Wetland (Disturbed) 769 44 Alkali Vernal Pools 00 San Diego Mesa Claypan Vernal Pools 0 0 San Diego Mesa Hardpan Vernal Pools 260 0 Vernal Lake 16 0 Total 992,306 64,599

1 The total area of the Plan Area is estimated to be 992,000 acres. At present, the area of the PIZ is approximately 64,600 acres (approximately six percent of the Plan Area). Due to slight differences in the boundaries for the Plan Area and vegetation data used in the analysis, there is a difference in the acreage presented in this table. As this table represents approximate acres, the area of each community has been rounded to the nearest acre. 2 Due to general mapping, portions of the Plan Area are not specifically categorized as a specific subcommunity. 3 Due to variances in the coastline for the Plan Area boundary and available regional data, vegetation mapping is not available for approximately 1,627 acres; therefore, these acres are listed as undefined.

4-6 TABLE 4-2 COMPARISON OF VEGETATION COMMUNITIES/LAND COVER TYPE TERMINOLOGY

City of San Diego Western Riverside County Water Authority NCCP/HCP MSCP Subarea Plan MHCP MSHCP Upland Habitats Agricultural General Agriculture Agricultural Lands Agriculture Agricultural Lands Agricultural Lands Extensive Agriculture (Row Agricultural Lands Agriculture Agricultural Lands Field Croplands Crops, Pastures) Intensive Agriculture (Dairies, Agricultural Lands Agriculture Agricultural Lands Dairy and Livestock Feedyards Nurseries, Chicken Ranches) Orchards and Vineyards Agricultural Lands Agriculture Agricultural Lands Grove/Orchard Chaparral, Coastal Chamise Chaparral (Granitic Chaparral Chamise Chaparral Chaparral Chamise Chaparral Chamise chaparral) Ceanothus crassifolius Chaparral Mixed Chaparral Chaparral Chaparral Chaparral Interior Live Oak Chaparral Chaparral Mixed Chaparral Chaparral Chaparral Northern Mixed Chaparral Chaparral Mixed Chaparral Chaparral Chaparral Northern Mixed Chaparral Chaparral Mixed Chaparral Chaparral Chaparral (Granitic) Northern Mixed Chaparral Mafic Northern Mixed N/A Chaparral Chaparral (Mafic) Chaparral Scrub Oak Chaparral Chaparral Scrub Oak Chaparral Chaparral Chaparral Southern Maritime Chaparral Southern Maritime Chaparral Maritime Chaparral Southern Maritime Chaparral N/A Southern Mixed Chaparral Chaparral Mixed Chaparral Chaparral Chaparral Southern Mixed Chaparral Chaparral Mixed Chaparral Chaparral Chaparral (Granitic) Southern Mixed Chaparral Mafic Southern Mixed N/A Chaparral Chaparral (Mafic) Chaparral Chaparral, Montane/Trans-montane Montane Chaparral Chaparral N/A Chaparral Chaparral Redshank Chaparral Chaparral N/A Chaparral Red Shank Chaparral Coastal Open Beach N/A N/A Beach N/A Southern Foredunes N/A Southern Foredunes Beach N/A

4-7 TABLE 4-2 COMPARISON OF VEGETATION COMMUNITIES/LAND COVER TYPE TERMINOLOGY (continued)

City of San Diego Western Riverside County Water Authority NCCP/HCP MSCP Subarea Plan MHCP MSHCP Coniferous Forest Big Cone Spruce-Canyon Oak Closed Cone Coniferous N/A N/A Lower Montane Coniferous Forest Forest Forest Mixed Coniferous Forest Closed Cone Coniferous N/A N/A Lower Montane Coniferous Forest Forest Southern Interior Cypress Cypress Forest N/A N/A Lower Montane Coniferous Forest Forest Torrey Pine Forest Closed Cone Coniferous Torrey Pines Forest N/A Lower Montane Coniferous Forest Forest Disturbed/Developed Bare Ground Disturbed Lands Disturbed Land Disturbed Residential/Urban/Exotic Disturbed Disturbed Lands Disturbed Land Disturbed Residential/Urban/Exotic Urban/Developed Land Disturbed Lands Developed Disturbed Residential/Urban/Exotic Exotic Landscapes Eucalyptus/Non-native Eucalyptus Woodland Eucalyptus Woodland Eucalyptus Residential/Urban/Exotic vegetation Ornamental Agriculture/Developed Developed Disturbed Residential/Urban/Exotic Grasslands Native Grassland (Valley Native Grassland Native Grassland Native Grassland Valley and Foothill Grassland Needle Grassland, Valley and Foothill Grassland) Non-Native Grassland Non-native Grassland Non-Native Grassland Annual (Non-native ) Non-native Grassland (Grassland) Grassland Oak Woodland and Forest Black Oak Forest Oak Woodlands Oak Woodlands N/A Black Oak Forest Black Oak Woodland Oak Woodlands Oak Woodlands N/A Black Oak Forest Coast Live Oak Forest (Dense Oak Woodlands Oak Woodlands Coast Live Oak Woodland Coast Live Oak Woodland Coast Live Oak Woodland) Coast Live Oak Woodland Oak Woodlands Oak Woodlands Coast Live Oak Woodland Coast Live Oak Woodland (Open Coast Live Oak Woodland) Engelmann Oak Forest Oak Woodlands Oak Woodlands Engelmann Oak Woodland Dense Engelmann Oak (Dense Engelmann Oak Woodland Woodland) Engelmann Oak Woodland Oak Woodlands Oak Woodlands Engelmann Oak Woodland Dense Engelmann Oak (Open Engelmann Oak Woodland Woodland)

4-8 TABLE 4-2 COMPARISON OF VEGETATION COMMUNITIES/LAND COVER TYPE TERMINOLOGY (continued)

City of San Diego Western Riverside County Water Authority NCCP/HCP MSCP Subarea Plan MHCP MSHCP Mixed Oak Woodland (Oak Oak Woodlands Oak Woodlands Coast Live Oak Woodland Oak Woodland Woodland) Sage-Scrub, Coastal Alluvial Fan Scrub Coastal Sage Scrub Coastal Sage Scrub (CSS) Coastal Sage Scrub Coastal Scrub Cactus Scrub Coastal Sage Scrub Coastal Sage Scrub (CSS) Coastal Sage Scrub Coastal Scrub Coastal Sage-Chaparral Scrub Coastal Sage-Chaparral Scrub CSS/Chaparral Coastal Sage-Chaparral Scrub Coastal Scrub Coastal Sage Scrub (Diegan) Coastal Sage Scrub Coastal Sage Scrub (CSS) Coastal Sage Scrub Diegan Coastal Sage Scrub Coastal Sage Scrub (Inland) Coastal Sage Scrub Coastal Sage Scrub (CSS) Coastal Sage Scrub Coastal Scrub Flat-topped Buckwheat Scrub Flat-topped Buckwheat Scrub Coastal Sage Scrub (CSS) Coastal Sage Scrub Coastal Scrub Maritime Succulent Scrub Maritime Succulent Scrub Maritime Succulent Scrub Maritime Succulent Scrub N/A Riversidean Alluvial Fan Scrub N/A N/A N/A Riversidean Alluvial Fan Scrub Riversidean Sage Scrub N/A N/A N/A Riversidean Sage Scrub Southern Coastal Bluff Scrub Coastal Bluff Scrub Coastal Bluff Scrub Southern Coastal Bluff Scrub N/A Sage-Scrub, Montane/Trans-montane Big Sagebrush Scrub (Great Coastal Sage Scrub N/A Coastal Sage Scrub Big Sagebrush Scrub Valley) Wetland Habitats Aquatic, Freshwater Non-vegetated Floodplain, Natural Flood Channel Natural Flood Channel Flood Channel N/A Channel, Lakeshore Fringe Open Freshwater (Freshwater, Open water N/A Fresh Water Open Water/Reservoir/ Open Water, Water) Aquatic, Marine Open Saltwater (Brackish Open water N/A Estuarine N/A Water, Deep Bay, Estuarine, Intertidal, Shallow Bay, Subtidal) Saltpan/Mudflats Salt Panne Salt panne Saltpan/Mudflats N/A Riparian Arrowweed Scrub Riparian Scrub Riparian Scrub Riparian Scrub Riparian Scrub Mule Fat Scrub Riparian Scrub Riparian Scrub Riparian Scrub Riparian Scrub Southern Arroyo Willow Riparian Forest Riparian Forest Riparian Forest Riparian Forest Riparian Forest Southern Coast Live Oak Riparian Forest Oak Riparian Forest Riparian Forest Riparian Forest Riparian Forest

4-9 TABLE 4-2 COMPARISON OF VEGETATION COMMUNITIES/LAND COVER TYPE TERMINOLOGY (continued)

City of San Diego Western Riverside County Water Authority NCCP/HCP MSCP Subarea Plan MHCP MSHCP Southern Cottonwood-Willow Riparian Forest Riparian Forest Riparian Forest Southern Cottonwood Willow Riparian Forest Riparian Forest Southern Sycamore Woodland Riparian Woodland Riparian Woodland Riparian Woodland Riparian Forest Southern Sycamore-alder Riparian Woodland Riparian Woodland Riparian Woodland Southern Sycamore-alder Riparian Woodland Riparian Woodland Southern Willow Scrub Riparian Scrub Riparian Scrub Riparian Scrub Southern Willow Scrub White Alder Riparian Forest Riparian Forest Riparian Forest Riparian Forest Riparian Forest Riparian (Disturbed) Arundo Scrub Disturbed Lands Disturbed Wetland Disturbed Wetland Arundo/Riparian forest Tamarisk Scrub Disturbed Lands Disturbed Wetland Disturbed Wetland Tamarisk Scrub Wetland Alkali wetlands (Alkali Seep, Alkali Marsh N/A Alkali Marsh Cismontane Alkali Marsh Alkali Marsh, Cismontane Alkali Marsh) Alkali Vernal Pools Vernal Pool Vernal Pool Vernal Pool Vernal Pool Freshwater Meadow or Seep Wetland Freshwater Marsh Freshwater Marsh Meadow (Montane) Freshwater Marsh (Coastal Freshwater Marsh Freshwater Marsh Freshwater Marsh Coastal and Valley and Valley Freshwater Marsh, Emergent Wetland) Montane Meadow Wetland N/A Freshwater Marsh Meadow (Montane) San Diego Mesa Claypan Vernal Pool Vernal Pool Vernal Pool Vernal Pool Vernal Pools San Diego Mesa Hardpan Vernal Pool Vernal Pool Vernal Pool Vernal Pool Vernal Pools Southern Coastal Salt Marsh Salt Marsh Salt Marsh Coastal Salt Marsh N/A Wetland (Disturbed) Disturbed Wetland Disturbed Wetland Disturbed Wetland N/A Vernal Lake N/A N/A N/A Vernal Pool N/A = Not applicable; Vegetation community/type not described and/or does not occur within plan are of regional conservation plan.

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4.2.1 Upland Communities

4.2.1.1 Agricultural

General Agriculture. Areas of unclassified agricultural use. This general category includes agricultural use areas that have been specified as extensive or intensive.

Extensive Agriculture (Row Crops, Pastures). Extensive agriculture includes all agricultural practices which use relatively little labor and resources on relatively large areas of land. Examples of extensive agriculture within the plan area may include: strawberry fields, lettuce farms, tomato farms, and pastures. Pastures fall into the agricultural heading if cultivation practices (e.g., seeding or irrigation) are used periodically to improve land for livestock forage.

Intensive Agriculture (Dairies, Nurseries, Chicken Ranches). Intensive agriculture includes all agricultural practices which use relatively high amounts of labor and resources on relatively small areas of land. This agricultural land type tends to have significant permanent buildings and installations on-site. Examples of intensive agriculture within the plan area may include: dairies, nurseries, cattle feedlots, and other Confined Animal Feeding Operations.

Orchards and Vineyards. Orchards and vineyards are intentional plantings of trees, shrubs, or vines maintained for food production or commercial use. These plantings tend to be perennial, can be artificially irrigated and fertilized, and usually do not involve intense annual soil disturbance. Examples of orchard and vineyard crops include: avocados, grapes, oranges, and apples.

4.2.1.2 Chaparral, Coastal

Chamise Chaparral (Granitic Chamise Chaparral). This low-growing chaparral community is dominated by chamise (), with limited shrub diversity and arid understory conditions. It occurs on poorly developed soils which are subject to extreme erosion if exposed by disturbance. Mature stands of chamise chaparral exhibit dense cover with little herbaceous understory or leaf litter.

Ceanothus crassifolius Chaparral. This chaparral community is dominated by hoary– leaf ceanothus (Ceanothus crassifolius) and chamise. This community usually occurs below 4,000 feet on xeric sites with shallow, stony soils.

Interior Live Oak Chaparral. This is a tall and dense chaparral community that is dominated by interior live oak (Quercus wislizenii), scrub oak (), and other evergreen shrub species. This community occurs on relatively mesic sites in valleys and foothills away from the coast, especially within the lower montane coniferous forest. A dense canopy and leaf litter component limit understory development.

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Northern Mixed Chaparral. This is a dense, near impenetrable community dominated by tall, broad-leafed shrubs. Scrub oak and chamise dominate this community which is often found on dry, rocky slopes. Northern Mixed Chaparral is general restricted to high elevation, north-facing slopes.

Northern Mixed Chaparral (Granitic). This community is characterized by tall, dense chaparral with growth limited to a few shrub species and little or no understory growth on poorly developed soils above substantial granite-derived surface rock. This habitat is generally restricted to higher foothill, montane, and transmontane elevations, and may occupy south-facing slopes of otherwise forested areas.

Northern Mixed Chaparral (Mafic). This community is characterized by tall, dense chaparral with growth limited to a few shrub species and little or no understory growth, occuring on depauperate soils high in magnesium and iron (Mafic soils) above substantial surface rock. This habitat is generally restricted to higher foothill, montane, and transmontane elevations, and may occupy south-facing slopes of otherwise forested areas.

Scrub Oak Chaparral. This tall chaparral community is dominated by scrub oak and associated with large, evergreen shrubs such as Ceanothus sp. Scrub Oak Chaparral generally occupies steep north-facing slopes in areas where it is typically interspersed with chamise chaparral.

Southern Maritime Chaparral. This is a low-growing, but sometimes densely canopied chaparral restricted to sandstone soils in areas heavily influenced by a coastal climate. A spectrum of annuals is present due primarily to cooler, moister conditions near the coast. The plant species composition of southern maritime chaparral is similar to southern mixed chaparral. Sensitive plant species characteristic of this community include Del Mar Mesa sand aster (Corethrogyne filaginifolia var. linifolia), Nuttall’s scrub oak (), summer-holly (Comarostaphylos diversifolia ssp. diversifolia), wart- stemmed ceanothus (Ceanothus verrucosus), and the federally endangered Del Mar ( glandulosa ssp. crassifolia). Southern maritime chaparral is restricted to sandy soils within the coastal fog belt in southern Orange County and in San Diego County.

Southern Mixed Chaparral (Granitic). This is a mid-sized to tall, woody chaparral dominated by chamise (Adenostoma fasciculatum) often situated on steep north- and east-facing slopes in soils derived from granite parent material. Drier locales preclude understory species diversity, whereas mesic conditions in the understory support a variety of ferns, subshrubs, herbaceous perennials, bulbs, and annuals. Characteristic species include manzanita (Arctostaphylos spp.), blue-colored lilacs (, C. leucodermis), mountain-mahogany ( minutiflorus), chamise (Adenostoma fasciculatum), mission manzanita (), toyon ( arbutifolia), holly-leaf cherry (), and fuchsia-flowered

4-12 4.0 Study Area Biology and Land Use gooseberry (Ribes speciosum). This habitat type occurs along the coastal foothills of San Diego County and , Mexico, typically below 3,000 feet above mean sea level.

Southern Mixed Chaparral (Mafic). Similar to southern mixed chaparral (Granitic), southern mixed chaparral (Mafic) contains mid-sized to tall, woody chaparral dominated by chamise often situated on steep north- and east-facing slopes. These , however, are located on depauperate soils high in magnesium and iron (Mafic soils). Although clear floristic distinctions are unclear, southern mixed chaparral (mafic) communities tend to have higher rates of endemism than Granitic derived chaparral.

4.2.1.3 Chaparral, Montane/Trans-montane

Montane Chaparral. Montane chaparral is characterized by dense stands dominated by several shrub species, such as manzanita (Arctostaphylos sp.) and lilac/buckbrush (Ceanothus sp.). It occurs on poorly developed soils underlain by substantial surface rock. This chaparral is restricted to higher foothill, montane, and transmontane elevations, and occupies south-facing slopes in forested areas.

Redshank Chaparral. Redshank chaparral is a tall-growing chaparral community dominated by redshank (). This community is usually found at higher foothill elevations, particularly in transmontane areas. Redshank chaparral occurs along the eastern limits of the Plan Area.

4.2.1.4 Coastal

Open Beach. Open beach habitats are sandy, unvegetated areas along the shoreline between the tideline and southern foredune communities.

Southern Foredunes. This distinctive habitat occurs beyond the high tide line and is composed of dunes with low-lying sandy areas supporting sparse woody shrubs and native annuals such as sand-verbena (Abronia spp.), sea-rocket (Cakile maritima), beach saltbush (Atriplex leucophylla), and coastal saltgrass (Distichlis spicata). This habitat type is extremely rare due to intensive recreational activities at beach areas.

4.2.1.5 Coniferous Forest

Big Cone Spruce – Canyon Oak Forest. This forest type is dominated big cone spruce (Psuedotsuga macrocarpa) with a shorter, dense sub-canopy of canyon oak () and a very sparsely vegetated herbaceous layer. This forest type can be found between 1,000 and 8,000 feet above mean sea level (Holland 1986).

Mixed Coniferous Forests. Mixed coniferous forest habitats include Coulter pine forest, ponderosa pine forest, Sierran coniferous forest, mixed oak-coniferous big pine/coulter

4-13 4.0 Study Area Biology and Land Use pine, mixed evergreen forest, and Jeffrey pine forest. These montane forests are primarily composed of conifers intermixed with occasional broad-leaved trees, especially . Conifer species include pines (Pinus coulteri, P. ponderosa, P. jeffreyi), white fir (Abies concolor), and incense cedar (Calocedrus decurrens). The understory is generally sparse and consists of tall-growing shrubs. Elevations range between 3,500 and 8,000 feet above mean sea level.

Southern Interior Cypress Forest, Tecate Cypress Forest. These fire-dependent forests consist of isolated stands of cypress (Cupressus forbesii or C. arizonica ssp. stephensonii), which are relictual elements from a more widespread Pleistocene flora. Forests of cypress are found at elevations between 1,000 and 5,500 feet above mean sea level. Young stands consist of densely packed adolescent trees that gradually give way to a more mature forest of fewer and larger trees. In the southern and better- developed habitats, the understory consists of more loosely associated chaparral and sage scrub species.

Torrey Pine Forest. Torrey pine forest is an open forest of relict Torrey pines (Pinus torreyana) and sandstone soils that occur along the coastline where significant fogs and mesic microhabitats are present. Much of this remaining habitat is protected in Torrey Pines State Reserve.

4.2.1.6 Disturbed/Developed

Bare Ground. Bare ground consists of unvegetated, disturbed areas. Areas with bare ground include: graded lands, land with significant topsoil disturbance, lands subject to repeated clearing for fuel management, construction staging areas, off-road vehicle trails, and old home sites.

Disturbed Habitat. Disturbed land is the area within a project site that, at the time a specific project is analyzed under CEQA or the pre-activity assessment is made (if no CEQA is required), the habitat mapping identifies as having less than 20 percent cover (by area or frequency of occurrence as determined during the site assessment) of native plants. The minimum mapping unit used to identify habitat and disturbed polygons will be appropriate for the site. Disturbed land will not require mitigation, except that non-native grasslands and delineated corridors/linkages may have less than 20 percent (or no) native plant species cover and still be treated as habitat that requires mitigation. The Plan relied on a regional vegetation data base for the initial habitat assessment, and as each project is initiated, the Plan’s vegetation mapping will be updated for those sites.

Urban/Developed Land. Urban/Developed lands include areas that have been permanently altered for human use. Urban/Developed lands include: parking lots, homes, commercial development, infrastructure, and ornamental landscaping.

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4.2.1.7 Grasslands

Native Grassland (Valley Needle Grassland, Valley and Foothill Needle Grassland). Native grasslands are found on clay substrates and support perennial native bunchgrass species such as needlegrass (Nassella spp. and Achnatherum spp.), wild rye (Elymus spp.), deergrass (Muhlenbergia spp.), and sacaton (Sporobolus ssp.). Native grasslands also support herbaceous perennial, annual, and bulb species such as blue-eyed grass (Sisyrinchium bellum), mariposa lily ( spp.), golden star (Bloomeria spp.), and clarkia (Clarkia spp.). Approximately 10 percent cover of native grasses will delineate native grassland from a non-native grassland. This vegetation type is scattered throughout the foothills, and is generally replaced in the higher mountains by montane meadow grassland species. Stands along the coast tend to cover relatively small areas and have often been heavily impacted by urban development. The majority of perennial grassland occurring in the Plan Area is found at upper elevations.

Non-native Grassland (Grassland). Non-native grassland is typified by a dense-to- open cover of annual and broadleaf, herbaceous grasses. Annual species comprise 50 to 90 percent of the vegetative cover, with most annuals being non-native species (SANDAG 2003). Shrubs and trees may be present, but do not comprise more than 15 percent of the vegetative cover. Non-native grassland indicator species include brome grasses (Bromus spp.), wild oats (Avena spp.), fescues (Vulpia spp.), mustards (Brassica spp.), and filarees (Erodium spp.). Non-native grasslands became widespread following the 19th century introduction of cattle and sheep herds. This introduced grassland often occupies deep loams and clays. Non-native grassland typically supports habitat for small mammals, reptiles, and raptor foraging. In the Plan Area, most non- native grassland likely developed as a result of past agricultural or urban development- related activities that occurred in native habitats.

4.2.1.8 Exotic Landscapes

Eucalyptus/Non-native Vegetation. Non-native eucalyptus woodlands are dense forests of tall Australian eucalyptus (Eucalyptus spp.) trees with allelopathic toxins that tend to exclude understory growth. This introduced woodland vegetation is well developed throughout the urban and coastal plains. Occasionally, other planted woodlands can be found at scattered locations. These woodlands provide foraging and breeding habitat for raptors and other avian species.

Ornamental. Ornamental landscapes include intentionally or actively planted areas usually associated with aesthetic improvement of developments. Ornamental landscapes are distinct from "natural", unplanned non-native areas that are the result of invasion by exotics following disturbance. Ornamental landscapes include: lawns, median plantings, golf courses, landscaped areas, street trees, etc.

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4.2.1.9 Oak Woodland and Forest

Black Oak Forest. The black oak forest community is a persistent subclimax vegetation community dominated by black oak (Quercus kelloggii). These even-aged, dense stands of black oak occur on mountain slopes, canyon bottoms, and upper foothill slopes (Holland 1986).

Black Oak Woodland. Black oak woodland is dominated by black oak and is found inland from between 2,500 to 7,000 feet. This community usually has a well developed understory and is associated with Ponderosa pine () (Holland 1986).

Coast Live Oak Forest (Dense Coast Live Oak Woodland). Coast live oak forest is very similar to the coast live oak woodland habitat described above except that it is characterized by having a denser, closed canopy. This habitat can be interspersed with madrone (Arbutus menziesii) and/or Coulter pine (Pinus coulteri). This habitat type is known to occur adjacent to coast live oak woodland in more mesic areas near the coast below 3,000 feet above mean sea level (Holland 1986).

Coast Live Oak Woodland (Open Coast Live Oak Woodland). This evergreen woodland is characterized by a sparse distribution coast live oak () with varying, relatively open understory components. Coast live oak woodlands can support an understory of perennial grasses, wild flowers, shrubs, and vines. Coast live oak woodland ranges from coastal canyons to montane valleys. This woodland habitat is typically found on north-facing slopes and in shaded ravines in drier areas (Holland 1986).

Engelmann Oak Forest (Dense Engelmann Oak Woodland). Engelmann Oak forest is similar to Engelmann Oak Woodland, except for tree density. Engelmann Oak Forests have a denser, more closed canopy than Engelmann Oak woodlands and contain a less dense understory. This habitat type is known to occur adjacent to other oak woodland communities in more mesic areas. (Holland 1986).

Engelmann Oak Woodland (Open Engelmann Oak Woodland). Mature Engelmann oaks (Quercus engelmannii), a sensitive tree whose primary range is within San Diego County, are typically found at mid-elevations. These woodlands are dominated by Engelmann oaks, and usually contain some coast live oaks as well. The understory is primarily composed of low-growing grasses and forbs. Much of Engelmann oak woodland habitat has been historically grazed in the plan area. Typically, one or two age classes of oaks are present, rather than a mix of class sizes. Engelmann oak woodland primarily occurs at foothill elevations below 4,000 feet (Holland 1986).

Mixed Oak Woodland (Oak Woodland). These broad-leaved, forest/woodland habitats exhibit a strongly tiered canopy of oaks (Quercus kelloggii and Q. chrysolepis) and mid- sized trees. A diverse understory of shrubs and herbaceous perennials is typical, often

4-16 4.0 Study Area Biology and Land Use including substantial amounts of downed logs and thick leaf litter. Occasional conifers may be present in addition to a mosaic of small glades and meadows. These habitats are present at mid- to upper-elevations (1,000 to 8,000 feet above mean sea level), and are uncommon in the foothills.

4.2.1.10 Sage Scrub, Coastal

Alluvial Fan Scrub. This vegetation community forms in washes and alluvial fans. It is characterized by a co-dominance of woody coastal sage scrub, chaparral, riparian plants and annual herbaceous species within a short distance of one another.

Cactus Scrub. Cactus scrub is a subtype of Diegan coastal sage scrub that supports a high density (greater than 60 percent) of prickly pear (Opuntia littoralis) (USFS 1997). There is no equivalent Holland (1986) vegetation class. In the Manual of California Vegetation (Sawyer-Keeler-Wolf 1995), the coast prickly-pear series is equivalent to cactus scrub, but this Sawyer Keeler-Wolf classification system does not specifically describe Diegan coastal sage scrub series dominated by coast cholla (Cylindropuntia prolifera) which can occur in coastal San Diego and Orange Counties.

Coastal Sage-Chaparral Scrub. This category represents a transitional habitat containing plant species representative of both sage scrub and chaparral vegetation. With respect to shrub height, density, and composition, this habitat more closely resembles sage scrub, as compared to the relatively tall and dense canopy of mixed chaparral.

Coastal Sage Scrub (Diegan). Diegan coastal sage scrub comprises low-growing, aromatic shrubs that are drought-. Diegan coastal sage scrub is found in coastal areas from County south into Baja California, Mexico. This community typically grows on sites with low moisture availability, steep, xeric slopes, or clay-rich soils that are slow to release stored water (Holland 1986). Typical native scrub species include California sagebrush ( californica), California buckwheat (), California encelia (Encelia californica), lemonadeberry (), and laurel ( laurina).

Coastal Sage Scrub (Inland) Inland sage scrub occurs within San Diego County at elevations above 1,000 feet above mean sea level.

Flat-topped buckwheat scrub. This scrub community is dominated by flat-topped buckwheat (Eriogonum fasciculatum) and is found in interior valleys, 10 to 24 miles from the coast. California sagebrush and laurel sumac can also be associated with this vegetation community.

Maritime Succulent Scrub. Maritime succulent scrub is a low-growing, relatively open vegetation community often dominated by drought-deciduous shrubs with a rich mixture

4-17 4.0 Study Area Biology and Land Use of cactus and other succulents. The vegetation is an extension of flora common in northern Baja California, Mexico, but uncommon in the U.S. It is differentiated from coastal sage scrub by the high density of (Simmondsia chinensis) and several cactus species and/or indicator species such as San Diego bur-sage (Ambrosia chenopodifolia) and cliff spurge (Euphorbia misera). This community intergrades with southern coastal bluff scrub on exposed headlands and bluffs and with coastal sage scrub on better developed, moister soils. It is reduced in the region due to urban development along the coast.

Riversidean Sage Scrub. This form of coastal sage scrub occurs throughout the plains and hills of western Riverside County. The community is characterized by low-stature, aromatic, drought-deciduous shrubs and sub-shrubs. It occurs on excessively drained soils or clay soils. Common shrub species include California sage brush, California buckwheat, and brittlebush (Encelia farinosa). The vegetation is typically a fairly open mixture of native shrubs, cacti, and non-native grasses. These species may vary depending on physical characteristics and successional status of the habitat.

Riversidean Alluvial Fan Scrub. Alluvial fan scrub is a Mediterranean-type restricted to floodplains and the periphery of drainages where deeply bedded, sandy alluvium supports plant species adapted to nutrient poor soils. Drought-deciduous, soft- leaved shrubs typically predominate, but evergreen shrubs, riparian species, and upland annual plants may all be present. Scalebroom (Lepidospartum squamatum) is considered an indicator species for this vegetation type. Although alluvial fan scrub is typically an inland vegetation community, tracts of alluvial fan scrub can also be found along the coastal plains. Additionally, alluvial fan scrub is occasionally found in the lower foothill drainages.

Southern Coastal Bluff Scrub. This vegetation community occurs on headlands and uplands that lie immediately behind and usually elevated above the beach dunes. Bluff scrub applies to an open mix of native succulents and low-lying shrubs that are adapted to moisture-laden winds and salt spray. Typical species include saltbush (Atriplex spp.), iceplant (Mesembryanthemum sp.), dudleya (Dudleya spp.), and sea-dahlia (Coreopsis spp.). Steady erosion and nearby horticultural plantings have introduced exotic species to these areas. This vegetation is rare due to intense urban development, and remains in only a few protected locations and along precipitous beach cliffs.

4.2.1.11 Sage Scrub, Montane/Trans-montane

Big Sagebrush Scrub. Big sagebrush scrub is an inland shrub community occurring at 4,000 to 9,000 feet. Big Sagebrush scrub is dominated by big sagebrush (Artemesia tridentata) and is found on a variety of soils and terrain. Other associated species include: blackbush (Coleogyne ramosissima), wingscale (Atriplex canescens), and rabbitbrush (Chrysothamnus nauseosus).

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4.2.2 Wetland Communities

4.2.2.1 Aquatic, Freshwater

Non-vegetated Floodplain,Channel, Lakeshore Fringe. Non-vegetated channels and floodways consist of dry washes, scoured channels, dry river beds, channelized floodways, and unvegetated margins of lakeshore. Plant cover in this habitat is typically absent or greatly reduced due to the severe seasonal water flow, shifting sediments, or a surface layer of bedrock that prevents plant establishment.

Open Freshwater (Freshwater, Open Water, Water). This category consists of inundated areas with no emergent vegetation. Open water areas include reservoirs, lakes, rivers, and . Vegetation, if present, consists of floating aquatic species.

4.2.2.2 Aquatic, Marine

Open Saltwater (Brackish Water, Deep Bay, Estuarine, Intertidal, Shallow Bay, Subtidal) This category consists of marine inundated areas with no emergent vegetation. This category includes bays, estuaries, brackish water, and coastal subtidal areas.

Saltpan/Mudflats. Saltpans and mudflats are unvegetated coastal wetland areas formed by the deposition of sediment and/or salts from tidal inundation. Saltpans and mudflats are typically associated with bays and estuaries.

4.2.2.3 Riparian

Arrowweed scrub. This community is composed of moderate to dense cover of Arrowweed (Pluchea sericea) below 2,500 feet above mean sea level. Additionally, Typha ssp., Scirpus spp, Juncus spp., and Distichlis spicata may occur sparsely throughout this community. Arrowweed scrub is a disturbance–maintained successional community, which occurs in stream banks, ditches, and washes with gravelly or sandy soil (Holland 1986).

Mule Fat Scrub. Mule fat scrub is a tall, herbaceous riparian scrub strongly dominated by mule fat (Baccharis salicifolia). It occurs along drainages with a fairly coarse substrate and a moderately deep water table. Mule fat scrub is developed and maintained by flooding or other disturbances but, in the absence of disturbance, may change, through successional processes to willow-cottonwood or sycamore-dominated riparian forest/woodland. Mule fat scrub typically occurs at elevations below 2,000 feet above mean sea level (Holland 1986).

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Southern Arroyo Willow Riparian Forest. Southern arroyo willow riparian forest is a riparian vegetation community that is dominated by arroyo willows (). This community is typically found along rivers and streams.

Southern Coast Live Oak Riparian Forest. Southern coast live oak riparian forests are open to locally dense evergreen woodlands primarily dominated by coast live oak. The forest understory is typically dominated by herbaceous species and tends to have a minimal shrub understory. Coast live oak woodlands are present bottomlands and outer floodplains along larger streams, on fine grained soils (Holland 1986).

Southern Cottonwood-Willow Forest. Southern cottonwood willow riparian forest is a riparian community dominated by cottonwood and willow trees. The understory typically consists of shrubby willows. This plant community is typically found along rivers and streams, where there is groundwater and frequent overflows (Holland 1986).

Southern Sycamore Woodland. Southern Sycamore Woodlands are sparse riparian communities dominated by California sycamore (Platanus racemosa) and coast live oak.

Southern Sycamore-Alder Riparian Woodland. Southern Sycamore-Alder Riparian Woodland is a tall, open canopy, broadleafed, winter-deciduous streamside woodland dominated by western sycamore (Platanus racemosa) and often white alder (Alnus rhombifolia). This vegetation community typically occurs in very rocky streambeds subject to seasonal high-intensity flooding. The dominance of white alder in these woodlands increases in abundance on more perennial streams, while western sycamore favors more intermittent streams (Holland 1986).

Southern Willow Scrub. Southern willow scrub is a dense riparian community dominated by broad-leafed, winter-deciduous willow trees (Salix spp.). This vegetation community is typically found along major drainages but also occurs in smaller drainages. The density of the willows typically prevents a dense understory of smaller plants from growing. The representative species typically grows in loose, sandy, or fine gravelly alluvium deposited near stream channels during flood flows. This community requires repeated flooding to prevent succession to community dominated by sycamores and/or cottonwoods (Holland 1986).

White Alder Riparian Forest. White Alder Riparian Forest can be found along permanent streams from 1,000 to 5,000 feet above mean sea level. This riparian community is dominated by white alder.

4.2.2.4 Riparian (Disturbed)

Arundo Scrub. Arundo scrub is found in disturbed riparian areas and washes. It is characterized by the dominance of Arundo donax, a large, bamboo-like plant from Mediterranean Europe and Southern Asia.

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Tamarisk Scrub. Tamarisk scrub is a type of riparian scrub dominated by non-native, highly invasive tamarisk (Tamarix spp.). This weedy plant community is usually a monoculture of tamarisk that has supplanted native wetland plant species. Tamarisk usually invades following disturbance. This plant community typically occurs in floodplains of drainages or intermittent streams, which are often in areas where high evaporation creates high salinity in the stream.

4.2.2.5 Wetland

Alkali Wetlands (Alkali Seep, Alkali Marsh, Cismontane Alkali Marsh). Alkali wetlands are characterized by saturated soils dominated by emergent, herbaceous monocots. These areas have high salt concentrations due to seasonal evaporation and poor flushing or leaching of the soils. Soils typically become dry, but may support standing water during the wet season. Most habitat areas occur as small, isolated stands in the foothills and lower mountains. Species typical of this habitat include yerba mansa (Anemopsis californica), spiny rush (Juncus acutus), and San Diego marsh elder (Iva hayesiana).

Freshwater Meadow or Seep. Freshwater seeps are localized microhabitats situated in moist or wet soil around springs or seeps, where wetland herbs and herbaceous perennials, especially sedges and grasses, are concentrated. Freshwater seeps are often associated with grasslands or meadows. This habitat differs from freshwater marsh in that it is usually low-growing and is not perennially inundated.

Freshwater Marsh (Coastal and Valley Freshwater Marsh, Emergent Wetland). Freshwater marsh habitat consists of saturated soils that remain wet through much of the year and support stands of perennial, emergent monocots. Uniform stands of bulrushes (Scirpus spp.) or cattails (Typha spp.) often characterize this habitat. Vegetation is substantially taller than in alkali marshes. Unlike freshwater seeps, freshwater marshes are relatively common at the edges of ponds, creeks, and riverbeds on the coastal plain, as well as into the foothills and mountains.

Montane Meadow. The montane meadow vegetation communities include wet and dry montane meadows and wildflower fields. Montane meadows support mesic fields of herbaceous perennials, bunchgrasses, and sedges which are adapted to a spring/summer growth cycle following heavy winter rainfall and snowmelt. High seasonal or semi-permanent moisture levels and poorly draining soils tend to preclude shrub growth. These meadows are distributed in low-lying fields with a substantial watershed throughout the mountains of the region at elevations between 4,000 and 9,000 feet above mean sea level.

Southern Coastal Salt Marsh. Southern coastal salt marsh and mudflats are coastal lagoon habitats that are characterized by low-energy tidal movement, river inputs, and increased sedimentation. Based on vegetation patterns, salt marshes can be segregated

4-21 4.0 Study Area Biology and Land Use into distinctive zones. Common species such as California cordgrass (Spartina foliosa) and pickleweed (Salicornia virginica) generally occur in the lower marsh areas subject to moderate tidal inundation closest to the waterline. Annual pickleweed, saltwort (Batis maritima), and sea-blite (Suaeda californica) generally occur at middle marsh elevations.

Wetland (Disturbed). Disturbed wetland habitat includes those areas which have been previously cleared and/or otherwise disturbed through human activity so that native wetland vegetation has been displaced. If there is a regulatory or legal action on the land to return it to a prior undisturbed condition, then the prior condition will be used to determine the status of the vegetation condition. Disturbed wetlands are characterized by the presence of hydric soils and/or dominated by nonnative or weedy wetland indicator species.

4.2.2.5.1 Vernal Pools

Vernal pool designation may include both road rut vernal pools and naturally formed pools. In San Diego County, natural vernal pools are usually either San Diego mesa hardpan vernal pools or San Diego mesa claypan vernal pools. Within the Plan Area in Riverside County, natural vernal pools may include vernal lakes, such as Skunk Hollow, or alkali vernal pools. A number of federally and/or state-listed plants and animals are restricted to these pool systems, including San Diego mesa mint (Pogogyne abramsii), Otay Mesa mint (Pogogyne nudiuscula), San Diego button celery ( ssp. parishii), Riverside fairy shrimp (Streptocephalus woottoni), and San Diego fairy shrimp (Branchinecta sandiegonensis).

Alkali Vernal Pool. Named after their saline-alkali soils, alkali vernal pools form over a large area in the inland valleys. There is an alkali vernal pool at the Salt Creek vernal pool complex in southwestern Riverside County (RCIP 2003). The size and configuration of alkali vernal pools varies based on annual rainfall and seasonal flood conditions.

San Diego Mesa Claypan Vernal Pool. These pools are similar to hardpan vernal pools except they have basins sealed by a thick veneer of clay. These pools occur on marine terraces on the coastal plain and have finer textured soils than the hardpan pools. They are often associated with mima mound topography. Claypan pools are often found in open fields and grasslands.

San Diego Mesa Hardpan Vernal Pool. This is a very low-growing plant community of herbaceous perennials and annuals that are adapted to seasonal ponding on hardpan iron and silica rich substrates relatively impervious to the downward flow of water. As a result, the rainfall in these coastal basins slowly evaporates over an extended period, allowing a unique assemblage of plants to grow during the interim. San Diego Mesa hardpan vernal pools are primarily found interspersed among open chaparral and sage scrub on the coastal marine terrace deposits of the northern portions of the city of San Diego.

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Vernal Lake. Large vernal pools that form in a basin and remain saturated for a longer duration are called vernal lakes. For some vernal lakes, vegetation in deeper portions may resemble freshwater marshes (RCIP 2003). The Skunk Hollow vernal pool is an example of a vernal lake. Located in Riverside County and covered by the MSHCP, Skunk Hollow is an isolated pool which supports several rare and endangered species (USFWS 2007b).

4.3 Sensitive Vegetation Communities

Vegetation communities considered sensitive by the Water Authority are rare or threatened in the region and support sensitive plant and wildlife species, including all wetlands, riparian habitats, waterways, coastal sage scrub, native grasslands, and oak woodlands.

4.4 Land Use

4.4.1 Existing Land Uses

General land uses within the Plan Area include residential development, commercial and business centers, industrial areas, public facilities such as government offices and education facilities, utilities, military installations, parks, agriculture, and open space. Approximately 25 percent of the area consists of parks and recreation areas. Figure 4-2 illustrates the general locations and boundaries of parks and preserve lands, including state and county parks and national parks. Military lands and lands covered by an existing or proposed city or county multiple species and/or habitat conservation plan are displayed on Figure 3-1.

Urban and residential development is more extensive in the lower elevations of the coastal plain of San Diego County and the inland valleys of southwestern Riverside County around Temecula. Residential land uses include single-family and multi-family residential housing, including townhouses and condominiums. Commercial land uses typically consist of business parks, retail shops, restaurants, and local businesses. Industrial areas are usually plant operations, such as manufacturing. Public facilities include government offices, schools, universities, and churches. Utilities include areas for power plants, water treatment plants, electrical substations, and associated easements and rights-of-way. Roads and paved areas are included in the public facilities land use category. Military installation areas include Camp Pendleton, MCAS Miramar, and Fallbrook Naval Weapons Station.

Agricultural uses are predominantly the orchard crops (e.g., avocado and citrus) of northern San Diego County, as well as tree crops and vineyards of foothills and valley

4-23 Diamond Valley Lake

ORANGEORANGE COUNTYCOUNTY Lake Skinner

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NCCP/HCP Plan Area Military Land 0 Miles 10 [ Existing/Planned Aqueducts and Pipelines San Diego County MSCP Preserve Lands Urbanized Areas Western Riverside County Parks and Preserves MSHCP Reserve Lands FIGURE 4-2 Land Use in NCCP/HCP Plan Area M:\JOBS2\3639\env\gis\NCCP\Fig4-2_NCCP.mxd 11/06/09 4.0 Study Area Biology and Land Use fringes of southwestern Riverside County. Agricultural uses (e.g., orchards, pastures, and dairy farms) are being rapidly displaced by residential development within the central portions of the Temecula Valley. Expansive areas of agricultural lands were also found on former ranched lands in southern San Diego County, notably on the Rancho Jamul Ecological Reserve (the former Daley Ranch) and Otay Ranch properties, and along the lowlands of the San Dieguito River Valley. Substantial tracts of this agricultural land are currently proposed for, or are actively being converted to, residential development.

Urban development covers much of the San Diego area, particularly along the coast and around the city of San Diego. However, open space and vacant lands occur in large tracts within the region. These areas are typically along ridges and mountain ranges, and in the east county area of San Diego County. Many parks, offering passive recreation opportunities such as hiking, are located in the undeveloped areas. Other activities associated with this land use include camping, biking, and picnicking.

4.4.2 Preserve Lands

This section discusses lands that have been preserved and managed (conserved) for biological diversity within the Plan Area. Within the Plan Area, these lands include state, county, and city parks, preserves, and ecological study areas, national forests, private and public lands covered by open space or conservation easements, and habitat mitigation banks. Most of the protected lands occur at higher elevations within the Cleveland National Forest, as well as within state parks and recreation areas. These areas are managed for joint use with a priority on protecting sensitive habitats and species, supporting large populations of larger wildlife species, and protecting populations of species requiring chaparral and montane habitats.

Existing conservation areas at lower elevations include the Lake Skinner-Shipley- Domenigoni Preserve complex in Riverside County; county, regional, and state parks; city preserves; and National Wildlife Refuges within coastal wetland complexes. Open space preserves within San Diego County include Blue Sky Ecological Reserve, Goodan Ranch, and Sycamore Canyon in Poway; El Capitan and Oak Oasis in Lakeside; Hellhole Canyon in Valley Center; Los Penasquitos Canyon, Mt. Gower, and Simon Open Space Preserve in Ramona; Otay Valley Regional Park; San Elijo Lagoon in Solana Beach; South Bay Biological Study Area in Imperial Beach; Volcan Mountain in Julian; and Wilderness Gardens in Pala. Day use regional parks include Mission Trails, Tijuana River Valley, Dos Picos, El Monte, Felicita, Flinn Springs, Otay Lakes, Pine Valley, Potrero, San Dieguito, Stelzer, and Sweetwater. National Wildlife Refuges (NWR) in southern San Diego County, including the San Diego NWR (which includes the San Miguel HMA owned by USFWS), the San Diego Bay Sweetwater Marsh NWR, the Tijuana Slough NWR, and the San Diego Bay South Bay NWR.

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The Water Authority’s Plan contributes to regionally significant conserved lands (i.e., Preserve Area) with the Crestridge HMA located near El Cajon; the San Miguel HMA within the San Diego NWR; and the Rancho Cañada HMA, which is part of the larger Monte Vista Ranch south of the community of Ramona in central San Diego County (Figure 4-3). The Water Authority’s Plan includes three wetland mitigation sites, including the existing Manchester HMA in the city of Encinitas, the proposed Tijuana River Valley HMA near the border, and the proposed San Luis Rey HMA in northern San Diego County. Finally, the Plan contributes numerous mitigation lands that were previously obtained and transferred to other entities for management (MMAs) as part of the regional conservation reserve system. Each of these HMAs is described in detail in Section 6.0.

4.5 Habitat Linkages and Wildlife Corridors

Wildlife linkages and corridors can function to increase the habitat value of blocks of habitat or to mitigate the effects of habitat fragmentation. Linkages are generally considered to be any connective land between larger blocks of habitat that promotes movement of a variety of species and/or processes. These connections can facilitate the movement of larger animals and can serve as “live-in” habitat for smaller species – both of which can improve gene flow among populations. Corridors are generally considered to be linear (often narrow) features that connect larger blocks of habitat and provide for movement, dispersal and migration of wildlife species. The linkage or corridor may not have continuous natural habitat (“stepping stones”) or may have very narrow constrictions (“bottlenecks”). The geographic area, time scale, and species of interest will affect the functional level of the linkage or corridor, which can be generally described as regional corridors and local corridors.

The Plan reviewed regional information and reports on core habitat areas and major corridors/linkages within the Plan Area. The Preserve Area and MMAs comprise portions of the core and linkages areas, and the Biologically Significant Resource Areas (BSRA) delineate habitat areas that may be important for maintaining key biological resources (see Figure 4-3). The regional wildlife corridors depicted on Figure 4-3 represent the general locations of habitat connections identified as missing linkages (South Coast Wildlands 2009). As Covered Activities are implemented under this Plan, it will ensure that Covered Activities do not significantly compromise core areas and linkages/corridors and that the guidelines for corridors/linkages are complied with (see Sections 6.4.2.1, 6.4.2.2, and 6.11.3.1).

Regional corridors are important in promoting dispersal of individuals that allow a species to repopulate areas (e.g., following a or other catastrophic event) and to exchange genetic materials among larger, disjunct populations. Due to the high incidence of habitat fragmentation in coastal , regional wildlife

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*# Upland MMA Sites # Regional Wildlife Corridors Urbanized Areas * Based on available digital data Military Land FIGURE 4-3 Conceptual Habitat Linkages in NCCP/HCP Plan Area M:\JOBS2\3639\env\gis\NCCP\Fig4-3_NCCP.mxd 10/12/10 4.0 Study Area Biology and Land Use corridors have begun to receive significant attention by Wildlife Agencies and conservation groups. The development of regional conservation plans with proposed reserve systems has increased the importance of and attention paid to conserving or establishing/enhancing these features. Despite this attention, substantial uncertainty surrounds the design of and key features for specific linkages and corridors (Beier, Majka and Spencer 2008). The San Diego MSCP adopted a general guideline that a significant corridor should have an average width of 1,000 feet to provide for most larger wildlife species’ movement, including some edge buffering. Pinch points less than 1,000 feet may be permissible for relatively short distances, but must have a minimum width of 400 feet for no more than 500 feet linear distance (City of San Diego 1998).

Local corridors often are short, relatively narrow linkages between two or more small, connected patches of habitat, which allows them to function as a larger block of habitat. The larger interconnected block enables viability and promotes population stability through regular genetic interchange, even though each individual habitat patch may be too small for the long-term survival of a wildlife population. The length and width (including any buffering from incompatible land uses/activities) and habitat patchiness within a corridor can greatly affect its effectiveness. The more effective wildlife corridors allow unobstructed movement of the species; however, some local linkage/corridors are comprised of closely-spaced patches of habitat. Limiting activities within and adjacent to local corridors can have a great effect on the suitability of corridors. Depending upon the particular species’ needs for a linkage/corridor, utility service corridors, emergency access routes, and recreational trails may function as corridors. This Plan does not define the specific width, patchiness, or other parameters for local corridors.

This Plan has been designed to maximize consistency with and complement other conservation planning efforts, with an emphasis on maintaining and/or expanding habitat linkages and wildlife corridors. Figure 4-3 shows conceptual conservation plan habitat linkages and wildlife corridors in San Diego County. As illustrated in Figure 4-3, the Crestridge HMA, San Miguel HMA, and Rancho Cañada HMA occur within county of San Diego MSCP core habitat linkages. The Tijuana River Valley and San Luis Rey River properties will also be located along key river corridors. In addition, Water Authority rights-of-way may be used as local wildlife linkages and corridors where they occur in native habitats and rural settings. Habitat linkages and wildlife corridors are important to the viability of regional planning efforts. In some instances, the presence of a utility corridor may serve to link habitat patches and ensure the long-term persistence of habitat connections. In other instances, surface features or prolonged construction activities may permanently or temporarily block corridors. As a result, the consideration of habitat linkages in other multiple species planning efforts was integrated into the development of compatibility criteria for Covered Activities occurring within the Plan Area.

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